Latch



Dec. 31, 1929. E. c. WILSON m'rcm Filed Sept. 27

1926 5 Sheets-Sheet l/we/zfar. Eli/2. C. ill/50m Dec. 31, 1929. E. c. WILSON 1,741,389

Filed Sept. 27. 1926 3 Sheets-Sheet 2 I220 en/ar E. C. WILSON Dec. 31,1929.

LATCH Filed Sept. 27, 1926 5 sheets sheet 3 I 227M172 6y Patented Dec. 31, 1929 U ETE STATE ELIHU 0. WILSON, OF LOS ANGELES, CALIFORNIA LATCH Application filed September 27, 1926. Serial No. 137,841.

This invention has to do generally with latches, and is more particularly concerned with latches of the type utilized in connection with swinging closures.

5 While it is unimportant to the invention as to the exact type of closure to which the latch is applied, 1 have illustrated and described two typical installations, and from an understanding of these, it will be readily 10 apparent how the latch may be applied in other situations. Consequently, the invention is in no way to be construed limited to the particular embodiments here illus trated and described.

While the term latch is descriptive of the entire device, hereinafter it will be used to designate only that element which is moved to andfrom latching engagement with one or the other of the hingedly connected members.

Fundamentally, a device embodying my invention includes a movable latch applied to one of the members which are to be latched, the latch being adapted to co-operate with the other of the members in a manner to hold it in predetermined position with respect thereto, and a latch-releasing element on that member which the latch engages, This is in oontradistinction to usual latching devices wherein the latch-releasing element is on that member which supports the latch.

By virtue of this provision, the latch may.

be mounted on the relatively stationary member, while the releasing device may be mounted on the swinging memb r or closure, it therefore being possible to incorporate the releasing device as a part of the handle by which the closure is hingedly moved. It then takes but a singe movement on the part of the operator both to disengage the latch and swing the closure about its hinged connection, This feature is particularly advantageous in that it allows the use of a T-shaped latch mounted in the particular manner hereinafter described and which has peculiar advantages of its own, and provides a release mechanism therefor which is peculiarly eflicient in operation and yet is simple of construction and capable of being reduced to such size and compactness that it does not protrude objectionably from the member on which it is mounted.

As a further feature, the elements of the latch are'so fashioned and arranged that after the latch has been freed from latching engagement, the elements coact in a manner to initiate swinging movement of the closure, an obvious feature of advantage in that it gives impetus to the swinging member so a lesser amount of manual exertion is required to swing the door open after it is unlatche'd and, under certain conditions, suilices to swing the door open sufficiently without the necessity of additional manual force. It also precludes the necessity of manually holding the releasing device in any particular position after the unlatching op eration in order that there may be no danger of automatic re-latching in the event the releasing means is let go.

During closing movement of the door and the latching operation, the releasing member does not engage the latch and hence no movement of said releasing member is necessary to the latching operation. There are several advantages gained by reason of this condition, as will be made apparent in the detailed specification.

In addition to the above, it is the general object of the invention to provide a device which automatically moves to latching position when the swinging member is swung to closed position, a device which positively holds against release except upon wilful and particular effort by the operator, and one which readily and easily yields to such effort when occasion arises for unlatching.

Other features of novelty and objects of the invention will be made apparent from the following detailed description, reference being had to the accompanying drawings in which:

Fig; 1 is an elevation of a. refrigerator or like structure to which an embodiment of my invention is applied;

Fig. 2 is a fragmentary, enlarged view of Fig. 1;

Fig. 3 is a section on line 33 of Fig. 2;

Fig. 4 is an enlarged view of Fig. 3 as viewed from the position of line 4- l;

Fig. 5 is an enlarged view of Fig. 3 as viewed from the position of line 5-5, the latch head being omitted;

Figs. 6, 7 and 8 are enlarged views gener ally similar to Fig. 3 but showing the mechanism in various stages of operation;

Fig. 9 is an enlarged section on line 99 of Fig. 2;

Fig. 10 is an enlarged view similar to Fig. 3 but showing a slight variation;

Fig. 11 is a view showing the latch applied to a. casing elevator or the like.

I have illustrated my device as applied to the door of a refrigerator, this type of structure serving particularly well to illustrate an advantageous installation of -my improved latch for reasons that are apparent. This choice of illustration, however, is in no way to be construed as limitative on the invention.

Numeral 10 designates a refrigerator or like structure having closures or doors 11 hingedly connected at 12 to the frame or stationary structure 13. While latching devices, generally designated at 14, may be applied with advantage to any or all the doors 11, it will only be necessary, of course, to describe one device in detail.

For the purpose of pointing out the association of the elements mounted on the two hingedly connected members, that is, frame or body member 13 and door or closure member 11, it will be helpful to consider the door as closed and the holding device in latching condition. It will be understood that in some instances both members upon which the latch elements are mounted are movable and that in other situations the particular latch elements shown here on the stationary and movable members, respectively, may be reversed in position, and therefore my broader claims are not to be considered as limited to the illustrated arrangement wherein a particular latching element is on a particular member, though ordinarily th arrangement is that shown.

Secured to member 13 by screws 15 is a plate 16, this plate carrying spaced ears or lugs 17 which rotatably support a shaft 18. A boss 19 at the end of shank 20 of T-shaped latch 21 is pinned at 18 to shaft 18 and has a nose 22 adapted to engage plate 16 in a man nor to limit counterclockwise movement of the latch, as viewed in Figs. 3 and 9. The latch head 23 is preferably beveled at one side to provide a cam face 24, this face functioning both in the latching and unlatching operation, as will be hereinafter described. Spring 25 is coiled about shaft 18 and its opposite ends 26 and 27 are anchored on said shaft and one of the ears 17, respectively. This spring normally but yieldingly holds latch 21 in the position of Fig. 9, nose 22 limiting the movement of the latch in its spring-urged direction. Preferably, though not necessarily, the position in which the latch is yieldably held by the spring is oneat right angles to plate 16 and hence member 13.

The shoulders formed by the underside of head 23 preferably, though not necessarily, are arcuate as illustrated at 26*, the arcs preferably being struck about the pivotal axis of the latch as a center.

A plate 28 is secured by screws 28 tomember 11 and carries spaced ears 29 which have projections 30 extending beyond the free end 31 of door 11 and provide latching shoulders 32, these shoulders preferably, though not necessarily, being complementary to shoulders or faces 26*, in other words, being substantially arcuate' and being concentric with shaft 18 when the door is closed. Projections 30 are spaced apart to take shank 20 between them, and shoulders 32 are adapted to underlie and preferably contact with head shoulders 26 when the door is closed. Projections 30 also have at their free ends cam faces 33, said faces preferably being extended to meet shoulders 32 at projection noses 34 and are adapted to coact with cam face 24. in a manner to be hereinafter described.

A latch releasing device generally 1nd1- cated at 35 is pinned at 36 (Fig. 5) to a shaft 37 which extends between and is rotatably supported in ears 29. Member 35 is in the form of a bell crank, one arm 38 providing a handle whereby the latch-release is operated and whereby the door is swung open or closed, and arm 39 forming a releasing cam. Arm 39 is in alinement with the shank and head of latch 21 and preferably, though not necessarily, carries at its free end a roller 10 adapted at certain stages during the operation of the device to engage cam face 24L and sometimes the contiguous face of shank 20. A spring 41 is anchored at its opposite ends to shaft 37 and the lowermost ear 29, and

urges member 35 in a counterclockwise direc-- tion, as viewed in Fig. 3, the fiat face 42 on said member engaging the flat face 43 (Fig. on plate 28 to limit this counterclockwise movement. When member 35 is at the limit of its spring urged movement, roller l0 and.

the end of arm 39 are preferably, though not necessarily, clear of cam face 23 so the bell crank has some lost motion before the roller.

is brought into contact with the latch, thus insuring that there will be no interference between-the latch and roller when the door is being closed.

It will be noted that the pintle of hinge 12 and the shafts 18, 37, are axially parallel, and that the latch and releasing member are both spring urged in the direction opposite door opening movement.

When it is desired to open the door, the operator grasps handle 38 and swings it in a clockwise direction, as viewed in Fig. 3,

against the action of spring 11. Roller 40 is thus brought into contact with cam face 24 and latch 21 is thereby swung in a clockwise direction, against the action of spring 25, until it clears nose 34. Thereafter, a continued pull on handle 38 serves to swing door 11 open. However, while the door may thus be opened by a pull on handle 38 after the latch is disengaged, continued pivotal movement of the bell crank and subsequent, reversed pivotal movement of the latch itself may aid in the door opening movement so,

after the latch is disengaged and the bell crank has been swung pivotally a slight amount after the disengagement, the handle 38 may be released without danger of an undesirable relatching operation. Generally, it will be noted that a continued pull on the handle unlatches the door and then initiates and may continue the door opening movement, this in spite of the fact that the releasing device swings, during such movement, in a direction opposite the swinging of the door. WVhile the operator is unconscious of the various movements he is causing by virtue of pivotal movement of the handle, being mer ly aware that a continuous sweeping movement of his arm both unlatches and swings the door open, the various elements of the latch act in a manner greatly to facilitate and quicken the operation.

Ordinarily, the operator continues his pull on the handle until the door is swung open, but, as mentioned above, should he release the handle at a certain stage of the operation, the latch acts in a manner to move the door open, so it is only necessary to impart coinparatively slight movement to the handle to swing the door entirely clear of the latch.

The above features may bebrought out by describing the act-ion as though it occurred slowly, though it will be understood that it is not essential to the operation of the device that all the steps described hereinafter occur, for certain of them are omitted if the handle is pulled continuously after the unlatching operation is completed. First referring to Fig. 6, member 35 is shown swung around to such a position that roller 40 has moved latch 20 almost from engagement with shoulders 32. A slight continued movement of handle 38 will clear the latch from said shoulders and therefore from projections so a mere pull on handle 38 will swing the door open. However, if, after the latch is disengaged from shoulders 32, handle 38 is given continued pivotal movement, roller 40 engages face 24, and member becomes a lever of the second class, the latch becoming the fulcrum since spring 25 acts to hold the latch with sufiicient force to appreciably resist movement thereof during this operation and since the door is now free to swing open. Shaft 37 is swung about roller 40, which rolls at the same time over face 24:, and thereby tends to swing door 11 open, as illustrated in Fig. 7. This movement brings noses 34 past shoulders 26 and therefore prevents automatic and undesired relatching should the.

handle be released immediately after said nose and shoulder pass out of alineme'nt.

As noted above, spring 41 tends to urge member 35 in a counter-clockwise direction as viewed in Fig. 3, that is, the spring urges handle 38 towards door 11, or considered otherwise, the spring tends to move the handle and door together; consequently, after noses 34 and shoulders 36 have been cleared, and assuming that the handle be held in the operators hand, not only does spring 21 act through the latch against member 35 in a manner tending to spring the door open, but spring 41 by tending to move the door towards handle 38 gives the door opening impetus.

WVith the parts in the positions of Fig. 7, release of handle 38 allows spring 41 to re turn crank 35 to the position of Fig. 3. Spring 25 acts to swing latch 20 in a counterclockwise direction, as viewed in Fig. 7 or to follow roller 40, bringing cam faces 24 into contact with cam faces 33 and, by reason of the relative shapes of the cams, this cam coaction tends to swing door 11 further in an opening direction (see Fig. 8). The door opening impetus created by the lever and cam action thus described, tends, of course, to open the door a considerable distance even though the handle may have been released immediately after nose 34; and shoulders 26 passed, and, in some situations, the door may be completely opened under these influences.

As soon as the latch is cleared by the door,

spring 25 moves the latch to normal position, nose 22 engaging plate 16 to stop springurged latch-movement so the beveled side of head 23 lies in the path of projections 30 but not in the path of the door, proper.

' In order to relatch the door, the latter is merely swung towards closed position, cam faces 33 then engaging the latch head to swing the latch against its spring'until the door is fully closed, at which time noses 34 clear shoulders 26 and allow the spring 25 to return the latch to operative position.

It will be noted that the elements are so relatively associated that roller and hence member 35 are not operatively engaged by latch 20 during closing or latching movement of the door, spring 37 insuring that member 35 be held in a position of clearance. As a result of this capacity of latching without movement of the releasing mechanism, several advantages are gained. F or instance, vibration and wear of parts are reduced to a minimum; less force is required to accomplish the latching, due to the elimination of resistance from the latching device; and, since the handleby which thedoor is moved is a part of or moves with the releasing device, the handle may be grasped while the door is pushed closed and latched without an, aocorrpanying movement of the operators hand necessitated by virtue of handle movement.

It will be noted that by virtue of the particular type of engagement between the latch head. and shoulders 32, especially with regard to their relation to the pivotal axis of the latch and the door, that the rotative movement of the latch necessary to unlatch the door cannot be imparted by opening movement of the door, this being an important feature in any situation where there may be internal pressure against the door.

In Fig. 10 I have shown a slight variation in that the relative shapes of shoulders 26 and 32 are such that movement of the latch in its spring-urged direction tends to cause cam action which insures a tight closing of the door. This situation may be brought about, for instance, by making one or the other of the shoulders eccentric with relation to the pivotal axis of the latch. Thus shoulder 26 is eccentric with relation to the shaft 18 and has a wedging action on shoulder 32 when it contacts therewith. By altering nose 22 so it does not engage plate 15 when the latch is in the position of Fig. 10, it will be seen that thereis provision for additional latch movement so the wedging action and consequent tight door-closing above described may occur even though the cam faces or the pivotal connection of the latch become worn. However, nose 22 is of sufficient length to limit the movement of the latch in its spring-urged di rection so that it may not pass to a position where it would interfere with the self-latching of the door. Of course, the cam or wedge action just described may be arrived at in manners other than by providing arcuate, ec-

centric cam faces, without departing from the spirit and scope of the invention.

In Fig. 11 I have shown the latching device as applied to an elevator for well casing and the like, parts in this view corresponding to parts shown in the other view being given the same reference numerals with the addition of the exponent b.

In the elevator or pipe encircling device, body member 13 corresponds to frame or supporting member 13 of the other figures, while the gate 11*, hinged to member 13 at 12 corresponds to the door or closure 11 of said figures. In such a construction it is preferable, though not necessary, that ears 17 and 29" be integral with members 13 and 11*, respectively. Otherwise, the construction is generally similar to that previously described, and since the device is adapted to operate in the same manner as when applied to a closure of the initially described structure, it is unnecessary here to enter into a discussion of the operation of this variational embodiment.

It will be understood the drawings and description are to be considered merely as illustrative of and not restrictive on the broader claims appended hereto, for various changes in design, structure and arrangement may be made without departing from the spirit and scope of said claims.

I claim:

1. In a device for latching the swinging end of a hingedly mounted member to another member towards and away from which the first mentioned member swings, a substantially T-shaped latch movably connected to one of the members and adapted to co-' operate with spaced shoulders on the other member, when the two members are in predetermined relative positions, to hold said other member from swinging away from said one member; and means on said other member adapted to be moved to engage the latch and move it from said cooperative association with said other member.

2. Ina device for latching the swinging end of a hingedly mounted member to another member towards and away from which the first mentioned member swings, a substantially T-shaped latch movably connected to one of the members and adapted to cooperate with spaced shoulders on the other memher, when the two members are inpredetermined relative positions, to hold said other member from swinging away from said one member; and means onsaid other member ar ranged between said shoulders and adapted to be moved to engage the latch and move it from said cooperative association with said other member. V

3. In a device for latching the swinging end of a hingedly mounted member to another member towards and away fromwhich the first mentioned member swings, a sub stantially T-shaped latch movably connected to one of the members and adapted to cooperate with spaced shoulders on the other member, when the two members are in predetermined relative positions, to hold said other member from swinging away from said one member; and means on said other member arranged between said shoulders and adapted to be moved to engage the head of the latch and move it from said cooperative association with said other member.

4-. In a device for latching a door to a memher with relation to which the door is movable to and from closed position, a latch movably mounted on said member for move ment into and out of latching engagement with the door, a releasing member movably mounted on the door and movable against the latch to release it from such engagement, a spring applied to the latch and adapted both to act through the latch against the releasing member to give opening impetus to the door after said latch is moved from latching engagement and tending subsequently to move the latch to latching position, and a second spring acting betwen the door and the releasing member and tending at all times to move the releasing member out of engagement with the latch.

5. In a device for latching a door to a member with relation to which the door is movable to and from closed position, a substantially T-shaped latch movably connected to the member and adapted to cooperate with spaced shoulders on the door to hold said door closed, and releasing means on the door adapted to be moved to engage the latch and move it from said cooperative association with the shoulders.

6. In a device for latching a door to a member with relation to which the door is movable to and from closed position, a substantially T-shaped latch pivotally mounted on the member and adapted to be moved pivotally in one direction into cooperative latching engagement with spaced shoulders 0n the door to hold said door closed, a pivotally mounted releasing member on said door adapted to be moved pivotally to engage the latch and move it from such cooperative engagement with said shoulders, and a spring tending to move the latch in said one direction.

7. In a device for latching a door to a member with relation to which the door is movable to and from closed position, a substantially T-shaped latch pivotally mounted on the member and adapted to be moved pivotally in one direction into cooperative latching engagement with spaced shoulders on the door to hold said door closed, a releasing member, said member embodying a cam in alinement with the latch and mount ed on the door for pivotal movement about an axis substantially parallel to the pivotal axis of the latch and an operating handle movable away from the door to move the cam against the latch and thereby move said latch out of latching engagement, a spring applied to said releasing member tending to move said handle towards the door and the cam away from the latch, and a second spring applied to the latch and tending to rotate the latch towards the cam.

In witness that I claim the foregoing I have hereunto subscribed my name this 9th day of September 1926.

ELIHU C. WILSON. 

